SB-10044962-1193

M a c k Tr u c k s , I n c .
Greensboro, NC USA

Field Serv ic e B ulletin
Tr u c k s

This Field Service Bulletin replaces bulletin, “EGR Differential Pressure
Sensor Pin Fretting", PV729–FSB293–007 (USA41828) dated (04/2010).

Date

Group

No.

Release

Page

7.2012

293

007

03

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EGR Differential Pressure Sensor Pin Fretting
CHU, CXU, GU, MRU
MP8

F S B 2 9 3 - 0 0 7 , E G R D i ff e r e n t i a l P r e s s u r e S e n s o r
Pin Fretting
(J uly 2012)
Severe fretting damage of the engine exhaust gas recirculation differential pressure sensor’s
(EGR differential pressure sensor) connector may cause an unreliable signal to the sensor on
MACK MP8 EPA2007 engines. The unreliable signal will generate diagnostic trouble codes
(DTC’s) MID 128 PID 411 FMI 3, 5, 12. If these DTC’s are logged and pin fretting is identified
as the cause of the DTC’s; the EGR differential pressure sensor, part number 21442662
should be replaced by the upgraded EGR differential pressure sensor 21713917 with a potted
pigtail, potted connector. The EGR differential sensor wiring harness kit 21560217 is used to
replace the existing connector from the differential EGR sensor with a four-pin DIN connector.
The new EGR differential pressure sensor with the kit will eliminate pin fretting and increase
the reliability of the EGR differential pressure sensor signal.
N o t e : This bulletin does not apply to Mack Trucks Australia.

W2074855

PV729-- FSB293-007_M

USA54413

M a c k Tr u c k s , I n c .
Field Service Bulletin

Date
7.2012

Group

No.

Release

293

007

03

E G R D i ff e r e n t i a l P r e s s u r e S e n s o r W i r i n g H a r n e s s K i t 2 1 5 6 0 2 1 7
Item

Desc rip tio n

P art N u mber

QTY

1

Brown wire w/Pre-crimped terminal and wire

N/A

1

2

White/Brown wire w/Pre-crimped terminal and wire

N/A

1

3

White/Green wire w/Pre-crimped terminal and wire

N/A

1

4

DIN four-pin Connector Housing

984849

1

5

Sealing Plug

970771

1

6

Backshell

3985598

1

7

Shrink Splice

6781769

3

8

Convoluted Tubing 150mm (5.9 in)

20739102

1

9

Bracket

21573079

1

10

Connector Attachment Ring

3963413

1

11

M8 Fastener

946470

1

12

Cable Tie

948211

1

13

Cable Tie

980881

1

14

Retainer

25375554

1

P roc edu re
You must read and understand the precautions and guidelines in Service Information,
group 29, "General Safety Practices, Engine" before performing this procedure. If you are
not properly trained and certified in this procedure, ask your supervisor for training before
you perform it.
1 Secure the vehicle for service by parking it on a flat level surface, applying the parking
brake, chocking the rear wheel, and placing the transmission in neutral or park.
2 Remove all cables from ground (negative) battery terminals to prevent personal injury from
electrical shock.
3 Locate EGR differential pressure sensor and disconnect harness.

W2074856

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M a c k Tr u c k s , I n c .
Field Service Bulletin

Date
7.2012

Group

No.

Release

293

007

03

4 Remove backshell and cut harness wires to EGR differential pressure sensor at the back
of the connector.

W2074857

5 Remove convoluted tubing and cut wires to 30mm (1.18 in) from the front edge of the Tfitting.

W2074858

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M a c k Tr u c k s , I n c .
Field Service Bulletin

Date
7.2012

Group

No.

Release

293

007

03

6 Strip 5mm (0.2 in) of insulation from the end of each wire and pre-crimped terminal
assembly.
N o t e : The wire colors may be obscured by paint overspray during manufacturing. Clean
wires or trace wires to splice joint for proper color matching during wire splicing.

W2074859

7 Using crimp tool, join the appropriate pre-crimped terminal and wire with shrink splice
6781769 to the corresponding stripped wire at the T-fitting, (Brn to Brn, W/Brn to W/Brn,
and W/Grn to W/Grn).

W2074860

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M a c k Tr u c k s , I n c .
Field Service Bulletin

Date
7.2012

Group

No.

Release

293

007

03

8 Using hot air gun, heat shrink butt splices until sealant is visible around ends of splices.
9 Insert the spliced wires through the end of the convoluted tubing 20739102 until the
terminals exit the other end.
10 Open the T-fitting and assemble convoluted tubing to the T-fitting. Snap the T-fitting tight
around the convoluted tubing.

W2074861

11 Push convoluted tubing back from the end of the pre-crimped terminal 40mm (1.6 in).

W2074862

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M a c k Tr u c k s , I n c .
Field Service Bulletin

Date
7.2012

Group

No.

Release

293

007

03

12 Assemble the pre-crimped terminal and wire assemblies to DIN connector housing 984849
as shown in table below. Assemble sealing plug 970771 to connector housing position 3.

W2074863

D IN C onne c to r H o us i ng W ire A s s embl y an d P l ug P os it ion s
Wire Ass embly

P lug P osition

White/Green (+5V)

DIN Connector Position 1

Brown (Signal)

DIN Connector Position 2

WHite/Brown (GND)

DIN Connector Position 4

Sealing Plug

DIN Connector Position 3

13 Assemble backshell 3985598 to convoluted tubing and Din connector. Snap backshell
assembly tight around convoluted tubing and DIN connector.

W2074864

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M a c k Tr u c k s , I n c .
Field Service Bulletin

Date
7.2012

Group

No.

Release

293

007

03

14 Assemble bracket 21573079 to coolant pump housing using fastener 946470. Tighten
fastener to 24 ± 4Nm (18 ± 3 lb-ft).

W2074865

15 Remove old EGR differential pressure sensor 21442662.
16 Install new EGR differential pressure sensor 21713917 with existing hardware. Tighten
fasteners to 24 ± 4Nm (18 ± 3 lb-ft).

W2074866

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M a c k Tr u c k s , I n c .
Field Service Bulletin

Date
7.2012

Group

No.

Release

293

007

03

17 Secure harness from EGR differential pressure sensor to bracket using connector
attachment ring 3963413.

W2074868

18 Assemble cable tie (part number 980881) and bracket as shown in figure below.

W2074870

Page
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M a c k Tr u c k s , I n c .
Field Service Bulletin

Date
7.2012

Group

No.

Release

293

007

03

19 Route DIN connector to bracket and assemble connectors.
N o t e : Route harness for DIN connector so that tubing does not make contact with metal
parts.
20 Secure harness assembly for DIN connector using cable tie part numbers 980881 and
948211.

W2074855

21 Connect all ground cables to batteries.
22 Start engine, check for operation codes that may be present, and clear.
23 Perform a learned data reset in Premium Tech Tool (PTT) before returning to service.
N o t e : Due to the electronic control module’s self-learning capabilities, it is necessary to
reset the learned data parameters after replacing or servicing certain components. This
allows the electronic control module to calibrate itself to the new component. Using Tech
Tool, perform Calibrations 2549-07-03-01 Function Monitoring Parameters, reset the
parameter related to the component replaced or serviced.
R ei mbu rs ement
Thi s repai r may be el igi bl e for rei mbu rs ement i f a produ c t fa il ure w as e x pe rien c ed
w i t h i n t i m e a n d m i l e a g e l i m i t s o f t h e a p p l i c a b l e Wa r r a n t y c o v e r a g e . R e i m b u r s e m e n t
is obta ine d v i a the no rmal c l aim handl i ng proc es s .
C l a i m Ty p e ( u s e d o n l y w h e n u p l o a d i n g f r o m t h e D e a l e r B u s . S y s . )

01

Labor Code
Primary Labor Code

2732b-19-80
0.7 hrs.

Caus al P art

21442662

MACK Trucks North America engages in a continuous program of testing and evaluating to
provide the best possible product. MACK Trucks North America, however, is not committed
to, or liable for updating existing chassis.

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